Rapid tuning of a laser by use of electro-optical or acusto-optical techniques has been heretofore known. The article in Applied Physics Letters Vol. 24, No. 2, pp 85-87 (1974) by J. M. Telle and C. L. Tang discloses a laser tuner of the electro-optical type which is not only rapid but also permits tuning over a broad tuning range. Because the cavity decay time, in particular for the cw Dye Laser, is on the order of 100 nsec. and because the cavity buildup time from the spontaneous emission power level is also on this order, it was heretofore believed impossible to tune the laser over a significant wavelength range in a time less than about 0.1 .mu.sec. Many potential applications (e.g. optical pulse compression and time-resolved spectroscopy) demand wavelength scanning in a time much less than 0.1 .mu.sec.; therefore, electronically tunable lasers heretofore were not considered for such use.